The present invention relates to an excavation method and apparatus for accessing underground pipes of pipelines for gas, oil, and the like, generally defined as pipelines, for maintenance and/or restoration and/or repair.
It is known that underground pipes of pipelines for oil, gas, and the like are subjected, in the course of time, to various maintenance operations and particularly to the total or partial restoration of the outer protective sheathing of the pipes.
Such maintenance operations are generally performed without interrupting fluid delivery and require the pipe to be exposed completely by removing the soil even in the region below the pipe, in order to allow wrapping and the like or, in any case, the regeneration of the sheathing along the entire circumference of said pipe.
Currently there are no valid methods or devices capable of performing excavations of this type in a mechanized and economically advantageous manner, removing the soil even in the region below the pipe, and conventional bucket excavators are simply used to perform an excavation that exposes the upper and side regions of said pipe, whereas the material below the pipe is removed manually by employing teams of workers equipped with conventional tools.
Obviously these excavation methods are excessively onerous and dangerous, since the use of bucket excavators requires extreme caution and can easily damage the pipe, with possible disastrous consequences. Furthermore, using manual tools to remove the soil below the pipe exposes workers to considerable risk of injury, both because landslips may occur in the excavations formed to the side of the pipe, where the workers must work, and because the pipe may give way.